The Knuckles statue, which is 10 inches tall, will come in two different editions. The Standard Edition will see 1,500 units made and cost $169.99 while the more flashy Exclusive Edition will only see 500 made and cost $189.99. The difference between them is simple: the Exclusive version has the lava rock Knuckles has pounded light up.
They're both quite pricey and limited, but there are probably Knuckles fans out there willing to shell out that much money to have their beloved Knuckles staring at them with his badass eyes (and if it's the Exclusive Edition light up) so here are links to pre-order both Standard and Exclusive. It's coming out sometime in 2012.